Mounting method and mounting device

ABSTRACT

A mounting method and a mounting device, the mounting method comprising the steps of, after positioning objects being bonded relative to each other, moving a movable wall positioned therearound until coming into contact with one object holding means to form a local chamber having a local enclosed space, enclosing both objects in the chamber, reducing the pressure in the chamber, moving the object holding means in a direction for reducing the volume of the chamber and moving the movable wall following the movement of the object holding means, and bonding both objects to each other by pressing, whereby, since the part to be bonded and its vicinity can be locally and efficiently enclosed separably from surroundings, and the local chamber capable of properly varying the shape of the enclosed space can be formed interlockingly with the bonding operation while maintaining the enclosed state even at the time of bonding, a specified mounting can be easily performed by a small device.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a mounting method and a mounting devicefor bonding objects such as chips or substrates to each other, andspecifically to a method and a device for forming a local chamberstructure having a movable wall for locally enclosing a bonding partfrom surroundings and carrying out mounting.

BACKGROUND ART OF THE INVENTION

Bonding objects to each other, for example, a mounting method forapproaching a chip to a substrate at a condition of face down andbonding both objects to each other by pressing electrodes of the chipand the substrate to each other (as needed, accompanying with heating)is well known. Further, a method is also well known wherein, at the timeof such a mounting, the mounting part is enclosed by surrounding it by achamber, after the inside of the chamber is set at a specifiedatmosphere and various treatments are carried out, or after the pressurein the chamber is reduced and the inside of the chamber is set at apredetermined vacuum condition, the mounting is carried out.

However, when such a conventional chamber structure is employed,substantially the whole of the chamber, whose inner pressure is reduced,is formed as a rigid structure, the mounting is carried out in thischamber, and therefore, the structure is formed so that the whole of themounting device or most of the mounting device is covered with thechamber. Therefore, the whole of the device including the chamberbecomes a large-scale device, and there is a problem that the devicebecomes large and the cost thereof increases. Further, because theinside volume of the chamber also increases, it takes a long time toreduce the pressure down to a predetermined vacuum degree or to replacethe atmosphere with a specified gas, and there is a case where it isdifficult to achieve a high vacuum-degree condition.

DISCLOSURE OF THE INVENTION

Accordingly, an object of the present invention is to provide a mountingmethod and a mounting device which can realize a local chamber structurecapable of locally and efficiently enclosing a bonding part and itsvicinity from surroundings and adequately varying the shape of theenclosed space interlockingly with the bonding operation whilemaintaining the enclosed condition even at the time of bonding, andwhich can quickly and easily achieving a predetermined vacuum degree orspecified-gas atmosphere by a small device using the local chamberstructure, thereby easily and inexpensively satisfying various requiredtreatment conditions or mounting conditions.

To accomplish the above object, a mounting method according to thepresent invention comprises the steps of positioning objects beingbonded to each other, which face each other with a gap, relative to eachother; moving a movable wall positioned around both objects until cominginto contact with one object holding means to form a local chamberhaving a local enclosed space and enclosing both objects in the localchamber; reducing a pressure in the local chamber to set an inside ofthe local chamber at a predetermined vacuum condition; and moving theobject holding means in a direction for reducing a volume of the localchamber and moving the movable wall following the movement of the objectholding means and bonding both objects to each other by pressing.

In this mounting method, although the mounting step accompaning bondingoperation can be started immediately after the above-described step forsetting a predetermined vacuum condition, various treatment steps or astep for setting various conditions can also be interposed beforestarting the mounting step.

For example, in the above-described mounting method, a method can beemployed wherein surfaces being bonded of the objects are cleaned in thelocal chamber by an energy wave or energy particle beam after thepressure in the local chamber is reduced to set the inside of the localchamber at the predetermined vacuum condition, and thereafter, theobject holding means and the movable wall following the object holdingmeans are moved and both objects are bonded to each other by pressing.

In this case, the cleaning by the energy wave or energy particle beamcan be carried out under the predetermined vacuum condition. Further, amethod can also employed wherein the cleaning by the energy wave orenergy particle beam is carried out after reducing the pressure in thelocal chamber to set the inside of the local chamber at thepredetermined vacuum condition, and after the cleaning and before thebonding, the inside atmosphere of the local chamber is replaced with anatmospheric inert or oxidizing gas. Although a plasma, an ion beam, anatomic beam, a radical beam or a laser can be used as the energy wave orenergy particle beam, in particular, it is preferred to use a plasmafrom the viewpoint of its easy handling, device cost and simplestructure.

Further, in the above-described mounting method, a method can also beemployed wherein a sealing material is applied onto a surface of oneobject before or after the pressure in the local chamber is reduced toset the inside of the local chamber at the predetermined vacuumcondition, and at the sealing material applied condition and under thepredetermined vacuum condition, the object holding means and the movablewall following the object holding means are moved and bonding parts ofboth objects are bonded to each other in the sealing material bypressing. As the sealing material, for example, a non-conductive paste(both of a paste formation and a film formation are included) or ananisotropic conductive paste (both of a paste formation and a filmformation are included) can be used.

Further, in the above-described mounting method, a method can also beemployed wherein the inside of the local chamber is set at an atmospherecondition of a specified gas after the pressure in the local chamber isreduced to set the inside of the local chamber at the predeterminedvacuum condition, and under the specified gas atmosphere condition, theobject holding means and the movable wall following the object holdingmeans are moved and both objects are bonded to each other by pressing.In this case, the inside of the local chamber can also be set at thespecified gas atmosphere condition with an atmospheric pressure. As thespecified gas, an inert gas (for example, argon gas), a non-oxidizinggas (for example, nitrogen gas), a reducing gas (for example, hydrogengas) or a substitutional gas (for example, a substitutional gas for afluorine group) can be used. For example, in a case where heat bondingis carried out using solder bumps, a fluxless bonding under anenvironment replaced with a nitrogen gas becomes possible.

Further, in the above-described mounting method, it is possible tocontrol the operational force of the movable wall at an adequate forcein accordance with an operation at the present time. For example, in thestep of setting the predetermined vacuum condition, by sealing theinside of the local chamber against outside by a contact force of themovable wall to the object holding means, the inside of the localchamber can be surely set at the predetermined vacuum condition.

Further, when the object holding means and the movable wall followingthe object holding means are moved, by substantially balancing a forceacting to the object holding means by the pressure in the local chamberand a contact force of the movable wall to the object holding means, itbecomes possible to suppress the force required for the movement of theobject holding means and the movable wall following the object holdingmeans to be small, thereby achieving a more smooth operation.

Furthermore, when the object holding means and the movable wallfollowing the object holding means are moved and one object is pressedto the other object, the pressing can be performed utilizing thepressure in the local chamber by reducing a contact force of the movablewall to the object holding means. For example, in a case where anupper-side object is held by a head having a cantilever structure, itbecomes possible to prevent the application of a moment due to thepressing of the head side in the above-described method, and ahigh-accuracy mounting becomes possible. Therefore, it becomes possibleto employ such a system.

A mounting device according to the present invention for bonding bothobjects to each other by pressing after positioning the objects relativeto each other with a gap, comprises a movable wall positioned around theobjects, capable of moving until coming into contact with one objectholding means to form a local chamber having a local enclosed spacecapable of enclosing both objects in the local chamber, and capable ofmoving in a direction for reducing a volume of the local chamberfollowing the movement of the object holding means; and a vacuum suctionmeans for reducing a pressure in the local chamber to set an inside ofthe local chamber at a predetermined vacuum condition.

In this mounting device, the mounting device preferably has a cylindermeans as means moving the movable wall. In such a structure, bycontrolling the supply pressures to the respective ports of the cylindermeans, the movable wall can be easily moved and the operational force ofthe movable wall can be controlled easily at a high accuracy. It ispreferred that a seal member capable of being elastically deformed isprovided at a tip of the movable wall. It becomes possible to easilybring the tip portion of the movable wall into close contact with theobject holding means by the seal member, thereby surely sealing theinside of the local chamber from surroundings. Moreover, also whenadjustment of parallelism between a chip and a substrate or adjustmentof alignment positions thereof is carried out, an amount required forthe adjustment can be absorbed by this seal member.

Further, the mounting device may have means for cleaning surfaces beingbonded of the objects in the local chamber by an energy wave or energyparticle beam. Further, the mounting device may have a gas supply meansfor replacing the inside of the local chamber with an atmosphere of aninert gas or a non-oxidizing gas at the time of and/or after cleaning bythe energy wave or energy particle beam.

The energy wave or energy particle beam is preferably a plasma, and whena plasma is used, each of the object holding means preferably has anelectrode for generating a plasma. In such a structure, it is possibleto easily carry out a desirable plasma cleaning in the local chamber.

Further, the mounting device can be constructed as a structure havingmeans for applying a sealing material onto a surface of one object. Asthe sealing material, a non-conductive paste or an anisotropicconductive paste can be used.

Further, a structure can be employed for the mounting device, whereinthe mounting device has a specified gas supply means for setting theinside of the local chamber at an atmosphere condition of a specifiedgas after the pressure in the local chamber is reduced to set the insideof the local chamber at the predetermined vacuum condition. As thespecified gas, as aforementioned, any of an inert gas, a non-oxidizinggas, a reducing gas and a substitutional gas can be used.

Further, the mounting device can be constructed as a structure whereinat least one object holding means has a heating means. In a case wheremounting accompanied with heating is required, this heating means canheat the bonding part.

Furthermore, in the mounting device, it is preferred that at least oneobject holding means has an electrostatic chucking means for holding theobject electrostatically. Because the electrostatic chucking means canexhibit an electrostatic holding force in a vacuum condition, even whenthe inside pressure of the local chamber is reduced, the holding stateof the object can be maintained with no problem. For this holding means,as shown in FIG. 1 described later, a three layer electrode pattern foran electrostatic chuck, a plasma electrode and a heater may be provided.

In such mounting method and mounting device according to the presentinvention, since the local chamber structure is formed by using themovable wall, it becomes possible to locally and efficiently encloseonly the portion of the objects facing each other, and to form a targetvacuum condition easily and inexpensively without using a large chamber,therefore, without making the whole of the device large. Further,because this movable wall is moved following the movement of one objectholding means and according to it the volume of the local chamber isproperly decreased, both objects can be pressed while a target conditioncan be maintained, and whereby a desirable bonding is carried out. As aresult, in spite of a small device, a reliable bonding state can beefficiently obtained, and a reliable mounting can be performed.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a vertical sectional view of a mounting device according to anembodiment of the present invention.

FIG. 2 is a process flow diagram of a mounting method according to afirst example of the present invention, carried out by using themounting device shown in FIG. 1.

FIG. 3 is a process flow diagram of a mounting method according to asecond example of the present invention, carried out by using themounting device shown in FIG. 1.

FIG. 4 is a process flow diagram of a mounting method according to athird example of the present invention, carried out by using themounting device shown in FIG. 1.

FIG. 5 is a process flow diagram of a mounting method according to afourth example of the present invention, carried out by using themounting device shown in FIG. 1.

THE BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, desirable embodiments of the present invention will beexplained referring to figures.

FIG. I shows a mounting device 1 according to an embodiment of thepresent invention. In FIG. 1, as objects facing each other with a gap, acase is exemplified where one object is a chip 2 and the other object isa substrate 3. A plurality of bumps 4 (in FIG. 1, two bumps 4 are shown)are provided on chip 2, and corresponding pads 5 (for example,electrodes) are provided on substrate 3. Chip 2 is held by a chipholding means 6 provided as one object holding means, and substrate 3 isheld by a substrate holding means 7 provided as the other object holdingmeans. In this embodiment, chip holding means 6 can be adjusted inposition in Z direction (in a vertical direction), and substrate holdingmeans 7 can be adjusted in position in X, Y directions (a horizontaldirection) and/or in a rotational direction (θ direction).

Where, chip 2 means any object with any form being bonded to a substrate3 regardless the kind and size, such as an IC chip, a semiconductorchip, an optoelectronic element, a surface mounting part and a wafer.Bump 4 means any kind of bump being bonded to pad 5 provided onsubstrate 3, such as a solder bump and a stud bump. Further, substrate 3means any object with any form being bonded to chip 2 regardless thekind and size, such as a resin substrate, a glass substrate, a filmsubstrate, a chip and a wafer. Pad 5 means any kind of pad being bondedto bump 4 provided on chip 2, such as an electrode accompanying withelectric wires, a dummy electrode accompanying with no electric wire,etc.

Further, in this embodiment, the part of chip holding means 6 directlyholding chip 2 and the part of substrate holding means 7 directlyholding substrate 3 are constructed as electrode tools 8 and 9 capableof functioning as electrodes for generating a plasma, respectively, anda heater is incorporated thereinto, the objects can be heated via atleast one electrode tool, an electrostatic chucking means isincorporated thereinto, and at least one object can be heldelectrostatically. Although the heater and the electrostatic chuckingmeans are not shown in the figure, known means can be used as both ofthem. In FIG. 1, label 10 a shows an electrode terminal for anelectrostatic chuck incorporated into the side of substrate holdingmeans 7, label 1 la shows a terminal for a plasma electrode, and label12 a shows a terminal for a heater, respectively, and electricity issupplied through an electrode connector 13. As the order pattern, it ispreferred that an electrostatic chuck, a plasma electrode and a heaterare disposed in order from the surface layer. Similarly, label 10 bshows an electrode terminal for an electrostatic chuck incorporated intothe side of chip holding means 6, label 11 b shows a terminal for aplasma electrode, and label 12 b shows a terminal for a heater,respectively.

Around both objects 2 and 3, provided is a movable wall 15 capable ofmoving until coming into contact with one object holding means (in thisembodiment, chip holding means 6) to form a local chamber structure (alocal chamber 14 is shown by the two-dot chain line in FIG. 1) having alocal enclosed space for enclosing both objects in the local chamber,and capable of moving in a direction for reducing the volume of localchamber 14 (in this embodiment, a downward moving direction) followingthe movement of the object holding means (in this embodiment, chipholding means 6). This movable wall 15 is formed in a cylindrical rigidstructure, and it can be moved vertically in FIG. 1 by a cylinder means19 having a movable wall lifting port 16, a movable wall lowering port17 and an inside sealing mechanism 18. A seal member 20 capable of beingelastically deformed is provided at a tip of movable wall 15, and at theabove-described contact condition, the inside of local chamber 14 can besealed and enclosed against the outside more surely.

In the side of substrate holding means 7, a vacuum pump 21 is connectedto local chamber 14 thus constructed, as a vacuum suction means forreducing the pressure in local chamber 14 to set the inside of localchamber 14 at a predetermined vacuum condition. The air or gas in localchamber 14 is sucked by vacuum pump 21 through a suction passage 22.Further, separately from this suction passage 22 or together with thissuction passage 22, a gas supply passage 23 for supplying a specifiedgas such as an argon gas (Ar gas) into local chamber 14 is provided inthe side of substrate holding means 7.

Using mounting device 1 thus constructed, the mounting method accordingto the present invention can be carried out in the following variousembodiments. Typical examples will be shown in FIGS. 2 to 5.

First, in the mounting method according to a first example shown in FIG.2, at the object setting step, chip 2 is held on the side of chipholding means 6 and substrate 3 is held on the side of substrate holdingmeans 7. Next, at the alignment step, a recognition means 24 (forexample, a recognition means having two sights of an upper sight and alower sight) is inserted between both objects 2 and 3, the upper andlower recognition marks for positioning are read, and based on the readinformation, substrate holding means 7 is adjusted in X and Ydirections, and further, as needed, in 0 direction, to control therelative positional relationship between both objects 2 and 3 within apredetermined accuracy range.

After the alignment, a pressure for the lifting movement of movable wall15 is supplied to cylinder means 19 though movable wall lifting port 16,and movable wall 15 is moved until the tip of movable wall 15 is broughtinto contact with the lower surface of chip holding means 6. By this, alocal chamber 14 substantially enclosed from surroundings is formed, andboth objects 2 and 3 are enclosed in this local enclosed space. Bysucking by vacuum pump 21 through suction passage 22 at the conditionformed with local chamber 14, the pressure in local chamber 14 isreduced (vacuum sucked), and the inside of local chamber 14 is set at apredetermined vacuum condition. As the predetermined vacuum condition,for example, a vacuum degree of 130×10⁻¹ Pa or less is employed. Becausean electrostatic chuck is used for chip 2 or substrate 3, even if thecondition is set at a high vacuum degree, the object holding state canbe maintained with no problem. In a case where this vacuum degree inlocal chamber 14 is maintained after this step, by keeping the contactforce of movable wall 15 to chip holding means 6 at a proper strength,the inside of local chamber 14 can be surely sealed from the outside andthe inside can be maintained at the predetermined vacuum condition.

Next, the surfaces being bonded of the objects are cleaned by an energywave or energy particle beam. Although this cleaning can be carried outeven in the above-described high-vacuum state, because a plasma is usedas the energy wave or energy particle beam in this example, in order togenerate the plasma efficiently and easily, a required amount of Ar gasis supplied into local chamber 14 through gas supply passage 23 afterthe pressure in local chamber 14 is reduced to set the inside of localchamber 14 at the predetermined vacuum degree, and the inside atmosphereof local chamber 14 is replaced with Ar gas while the inside of localchamber 14 is maintained at the predetermined vacuum degree.

At this state, in local chamber 14, a plasma is generated between theupper and lower electrodes (electrode tools 8 and 9), and the surfacesbeing bonded are cleaned by removing organic substances and foreignmaterials on the surfaces of the objects by the generated plasma. Bythis cleaning, the surfaces being bonded are activated. In this plasmacleaning under the Ar gas atmosphere, the irradiation direction of theplasma can be switched alternately by switching the polarities of theupper and lower electrodes alternately, and it becomes possible toefficiently clean both surfaces being bonded of chip 2 side andsubstrate 3 side.

Next, chip 2 and substrate 3, whose bonding surfaces have been activatedby the above-described plasma cleaning, are bonded to each other. In thebonding step, although chip holding means 6 is moved down and followingthe movement movable wall 15 in contact with chip holding means 6 isalso moved down, during this movement, because movable wall 15 is alwaysmaintained at a condition being brought into contact with the lowersurface of chip holding means 6, the good enclosed state of the insideof local chamber 14 can be maintained as it is although the volume oflocal chamber 14 is reduced. At that time, if a force acting to chipholding means 6 by the pressure in local chamber 14 (vacuum pressure) (aforce for moving chip holding means 6 down) and a contact force ofmovable wall 15 to chip holding means 6 are controlled at a constantrelationship, the moving-down force of chip holding means 6 can besuppressed small, and the control of a pressing force for bonding due tochip holding means 6 after the contact of chip 2 with substrate 3 isfacilitated.

Further, if a force acting to chip holding means 6 by the pressure inlocal chamber 14 (vacuum pressure) (a force for moving chip holdingmeans 6 down) and a contact force of movable wall 15 to chip holdingmeans 6 are substantially balanced, in a case where the head has acantilever structure, a moment is not generated, it is advantageous onparallelism and positional accuracy. Where, “substantially balanced”means that there is no problem even if there is a slight differencebetween vertical forces, because the axis of vertical movement can bemaintained. Further, even at the balanced state, because the contactforce does not vary, the good sealing condition can be maintained as itis.

Bumps 4 of chip 2 and pads 5 of substrate 3 are brought into contactwith each other and bonded to each other. Since both surfaces have beenactivated by the aforementioned plasma cleaning and organic substancesand oxides have been removed from the bonding surfaces, a roomtemperature bonding in vacuum condition becomes possible.

FIG. 3 shows a mounting method according to a second example. In thisexample, the process from the setting of the objects to the plasmacleaning under Ar gas atmosphere condition accompanied with switching ofelectrodes is substantially the same as that of the first example shownin FIG. 2. In this second example, after the plasma cleaning under Argas atmosphere condition and under the predetermined vacuum conditionaccompanied with switching of electrodes is performed, Ar gas is furthersupplied into local chamber 14 through gas supply passage 23, the insideof local chamber 14 is replaced with an atmospheric Ar gas (anatmospheric inert gas). Further, associated with that, the pressure ofthe movable wall lifting port is lowered down to a degree capable ofmaintaining the sealing.

Then, at the condition of the atmospheric Ar gas atmosphere, chipholding means 6 is moved down, following this movement movable wall 15in contact with the chip holding means 6 is also moved down, and bumps 4of chip 2 and pads 5 of substrate 3 are bonded to each other bypressing. Under the aforementioned vacuum condition, because a pressureis applied at a sealing portion of the movable wall, in a case where aslight inclination exists on the upper and lower holding means, there isa possibility that a moment generates and a positional shift in mountingat several-micron order may occur.

However, if the atmosphere is returned to an atmospheric pressurecondition and thereafter the mounting is carried out, such a moment isnot generated, and a higher accuracy mounting can be performed. At thattime, in this embodiment, the bonding is carried out furtheraccompanying heating. The heating can be carried out by theaforementioned incorporated heater. In this bonding step, because thebonding surfaces of chip 2 and substrate 3 are activated by the plasmacleaning under Ar gas atmosphere condition at the prior step, adesirable bonding can be performed by a relatively low-temperatureheating. Namely, a required metal bonding between bumps 4 of chip 2 andpads 5 of substrate 3 can be achieved by a low-temperature heating.

FIG. 4 shows a mounting method according to a third example. In thisexample, at the step of setting the objects, or at the step ofalignment, a sealing material 31 (in this example, a non-conductivepaste (NCP)) is applied onto the surface being bonded of one object (inthis example, substrate 3), and after the alignment, local chamber 14 isformed by lifting movable wall 14, and the inside thereof is vacuumsucked. At this step, first, air contained in the paste is deaerated.The inside of local chamber 14 is set at a predetermined vacuumcondition, chip holding means 6 and movable wall 15 are moved down, andbumps 4 of chip 2 are pressed onto pads 5 of substrate 3. At that time,although sealing material 31 having been applied is expanded towardoutside, because the sealing material 31 flows under the predeterminedvacuum condition, residual air can be suppressed. Then, at the sametime, or immediately after this step, bumps 4 of chip 2 and pads 5 ofsubstrate 3 are bonded to each other accompanying heating, and at thesame time, sealing material 3 1 is cured. If air remains at this time ofcuring sealing material 31, there is a fear that it remains at the formof voids by the increase of the volume due to the heating, but, becauseof a heat bonding under the predetermined vacuum condition, a voidlessbonding becomes possible.

FIG. 5 shows a mounting method according to a fourth example. In thisexample, solder ball bumps 4a capable of being heat-melting bonded areprovided as the bumps of chip 2. In this example, the process from thestep of setting the objects to the step of vacuum suction issubstantially the same as that of the first example shown in FIG. 2. Inthis fourth example, after the inside of local chamber 14 is set at apredetermined vacuum condition, the inside of local chamber 14 isreplaced with an atmosphere of a specified gas. In this example, anon-oxidizing gas, especially, a nitrogen gas (N₂ gas) with anatmospheric pressure is used as the specified gas. After the inside oflocal chamber 14 is replaced with the atmospheric nitrogen gas, chipholding means 6 and movable wall 15 are moved down, solder ball bumps 4a of chip 2 are pressed onto pads 5 of substrate 3, and they are heatbonded. Because of heat bonding in the nitrogen gas atmosphere, asecondary oxidation ascribed to heating can be suppressed, and at afluxless condition, bumps 4 a and pads 5 can be bonded at a highreliability.

As shown in FIGS. 2 to 5, in the present invention, various conditionscan be employed for the mounting formation. In any formation, localchamber 14 can be efficiently formed by the vertical movement of movablewall 15, and since movable wall 15 is vertically moved by cylinder means19, it can be moved down following the movement of chip holding means 6and a target atmosphere in local chamber 14 can be maintained even atthe time of bonding operation, a reliable bonding state can be achieved.

Thus, in the mounting method and the mounting device according to thepresent invention, since a local chamber is efficiently and easilyformed by a movable wall, and after the step for setting the inside ofthe local chamber at a predetermined vacuum condition, the objectholding means and the movable wall are moved in a direction decreasingthe volume of the local chamber while the inside of the local chamber isset at a target atmosphere and the state is maintained, and a desirablebonding can be performed, a reliable bonding state can be efficientlyobtained by a small device.

INDUSTRIAL APPLICATIONS OF THE INVENTION

The mounting method and the mounting device according to the presentinvention can be applied to any mounting performed in a predeterminedatmosphere, and in particular, they are suitable for a case requiring asmall device or a case requiring to form a specified atmospherecondition for mounting with a small amount of gas.

1. A mounting method comprising the steps of: positioning objects beingbonded to each other, which face each other with a gap, relative to eachother; moving a movable wall positioned around both objects until cominginto contact with one object holding means to form a local chamberhaving a local enclosed space and enclosing both objects in said localchamber; reducing a pressure in said local chamber to set an inside ofsaid local chamber at a predetermined vacuum condition; and moving saidobject holding means in a direction for reducing a volume of said localchamber and moving said movable wall following the movement of saidobject holding means and bonding both objects to each other by pressing.2. The mounting method according to claim 1, wherein surfaces beingbonded of said objects are cleaned in said local chamber by an energywave or energy particle beam after the pressure in said local chamber isreduced to set the inside of said local chamber at said predeterminedvacuum condition, and thereafter, said object holding means and saidmovable wall following said object holding means are moved and bothobjects are bonded to each other by pressing.
 3. The mounting methodaccording to claim 2, wherein said cleaning by said energy wave orenergy particle beam is carried out under said predetermined vacuumcondition.
 4. The mounting method according to claim 2, wherein saidcleaning by said energy wave or energy particle beam is carried outafter reducing the pressure in said local chamber to set the inside ofsaid local chamber at said predetermined vacuum condition, and after thecleaning and before the bonding, the inside atmosphere of said localchamber is replaced with an atmospheric inert or oxidizing gas.
 5. Themounting method according to claim 2, wherein said energy wave or energyparticle beam is a plasma.
 6. The mounting method according to claim 1,wherein a sealing material is applied onto a surface of one objectbefore or after the pressure in said local chamber is reduced to set theinside of said local chamber at said predetermined vacuum condition, andat the sealing material applied condition and under said predeterminedvacuum condition, said object holding means and said movable wallfollowing said object holding means are moved and bonding parts of bothobjects are bonded to each other in said sealing material by pressing.7. The mounting method according to claim 6, wherein said sealingmaterial is a non-conductive paste or an anisotropic conductive paste.8. The mounting method according to claim 1, wherein the inside of saidlocal chamber is set at an atmosphere condition of a specified gas afterthe pressure in said local chamber is reduced to set the inside of saidlocal chamber at said predetermined vacuum condition, and under saidspecified gas atmosphere condition, said object holding means and saidmovable wall following said object holding means are moved and bothobjects are bonded to each other by pressing.
 9. The mounting methodaccording to claim 8, wherein the inside of said local chamber is set atsaid specified gas atmosphere condition with an atmospheric pressure.10. The mounting method according to claim 8, wherein an inert gas, anon-oxidizing gas, a reducing gas or a substitutional gas is used assaid specified gas.
 11. The mounting method according to claim 1,wherein, in said step of setting said predetermined vacuum condition,the inside of said local chamber is sealed against outside by a contactforce of said movable wall to said object holding means.
 12. Themounting method according to claim 1, wherein, when said object holdingmeans and said movable wall following said object holding means aremoved, a force acting to said object holding means by the pressure insaid local chamber and a contact force of said movable wall to saidobject holding means are substantially balanced.
 13. The mounting methodaccording to claim 1, wherein, when said object holding means and saidmovable wall following said object holding means are moved and oneobject is pressed to the other object, the pressing is performedutilizing the pressure in said local chamber by reducing a contact forceof said movable wall to said object holding means.
 14. A mounting devicefor bonding both objects to each other by pressing after positioningsaid objects relative to each other with a gap, said mounting devicecomprising; a movable wall positioned around said objects, capable ofmoving until coming into contact with one object holding means to form alocal chamber having a local enclosed space capable of enclosing bothobjects in said local chamber, and capable of moving in a direction forreducing a volume of said local chamber following the movement of saidobject holding means; and a vacuum suction means for reducing a pressurein said local chamber to set an inside of said local chamber at apredetermined vacuum condition.
 15. The mounting device according toclaim 14, wherein said mounting device has a cylinder means for movingsaid movable wall.
 16. The mounting device according to claim 14,wherein a seal member capable of being elastically deformed is providedat a tip of said movable wall.
 17. The mounting device according toclaim 14, wherein said mounting device has means for cleaning surfacesbeing bonded of said objects in said local chamber by an energy wave orenergy particle beam.
 18. The mounting device according to claim 17,wherein said mounting device has a gas supply means for replacing theinside of said local chamber with an atmosphere of an inert gas or anon-oxidizing gas at the time of and/or after cleaning by said energywave or energy particle beam.
 19. The mounting device according to claim17, wherein said energy wave or energy particle beam is a plasma. 20.The mounting device according to claim 19, wherein each of said objectholding means has an electrode for generating a plasma.
 21. The mountingdevice according to claim 19, wherein said mounting device has means forapplying a sealing material onto a surface of one object.
 22. Themounting device according to claim 21, wherein said sealing material isa non-conductive paste or an anisotropic conductive paste.
 23. Themounting device according to claim 14, wherein said mounting device hasa specified gas supply means for setting the inside of said localchamber at an atmosphere condition of a specified gas after the pressurein said local chamber is reduced to set the inside of said local chamberat said predetermined vacuum condition.
 24. The mounting deviceaccording to claim 23, wherein said specified gas is an inert gas, anon-oxidizing gas, a reducing gas or a substitutional gas.
 25. Themounting device according to claim 14, wherein at least one objectholding means has a heating means.
 26. The mounting device according toclaim 14, wherein at least one object holding means has an electrostaticchucking means for holding said object electrostatically.